I saw two things in this article that I realized almost immediatly; one, The new blanks that are available today both Poly and EPS (due to their consistent densities) allow one to easily adjust rail volume from the deck. The norm with a Clark blank was to take it down to desired thichness from the bottom and to avoid cutting to deep into the deck. Cutting too deep into a Clark deck meant a soft deck. On todays' blanks if the deck is too domed one can safely bring it down to blend it. As Bill suggested changes in rail volume can be made from the deck and with today's consistent blanks there is no sacrifice to deck strength. Two, The other thing is the commonplace "beaked nose" of the 70's and early '80's. Certainly thinning out and rockering the nose as done in modern shortboards has also allowed shapers to alter rail volume in the front third of the blank. Like I said somethings have progressed but, alot of things remain the same. Lowel
I like using this tool. I record my favorite reference and use it to make new ones, with or without volume adjustment. The last one I made I added 1/16" more volume. Imo, deck roll, although related, is another design element.
Good way to compare profiles, but does not measure volume easily. Also, the two rail profiles you show have different shapes and volumes. What was mentioned earlier was changing volume without shape - just scaling up the profile.
Good way to compare profiles, but does not measure volume easily. Also, the two rail profiles you show have different shapes and volumes. What was mentioned earlier was changing volume without shape - just scaling up the profile.
Ok got it. I can do all that too.
I took that pic years ago, of two different unrelated boards, both boards work great for me.
My only point was to offer a simple cheap tool that eliminates some of the guesswork.
I've been on the software guys for years to produce a "longitutinal slice". All software has capacity to cut boards across the stringer (and it's easy 9though not emotionally) to slice a board up that way to get rail profiles). The thing hat amazes me about these profiles is how quickly the rail shape changes over say a 1" thick slice of a board. Doesn't seem that it should be much, but when you're handling a block of foam you sure feel it.
A longitudinal slice is needed to get rid of the bunny ears you see in so many machine cut boards, where the software does not merge slices as smoothly as the designer envisioned. Longitudinal slices would also permit accurate foiling of the rails front to rear (what NJ refers to in the middle of his post above). I personally believe that rail foiling should provide lift and drive (like a fin) when the board is on rail.
Watch vids carefully and you can see the nose of many board rising and falling through bottom turns as the rail foiling pops it out the water and the surfer counteracts to keep his line. I've moved my rail thick point forward to change the foiling characteristics. It's tricky moving rail thick point forward of rocker thick point. Keeping rocker thickness the same over the middle 1/3 of the board helps a bit with this.
PS this post shows the other thing that's changed since Bill's excellent article above (thanks for posting!) - machineheads have got into it and are trying to get the ideas to come out of zeros and ones rather than Skils (pun intended)
I think http://www.witchcraft.nu custom software uses longitudional curves for creating the foil, no crossections. However I would think that would be hard to edit. Showing a longitudinal slice on the other hand is relatively easy and something I could incorporate.
Watch vids carefully and you can see the nose of many board rising and falling through bottom turns as the rail foiling pops it out the water and the surfer counteracts to keep his line. I've moved my rail thick point forward to change the foiling characteristics. It's tricky moving rail thick point forward of rocker thick point. Keeping rocker thickness the same over the middle 1/3 of the board helps a bit with this.
Do you attribute this only to rail foil? To me it looks like there are several design elements fighting each other, but it's hard to tell (for me anyway) if it's the rocker that wants to turn at one radius while fins want to trun at another radius or some other element. Sometimes on vids the wobble and bump looks so bad that it's amazing the surfer manages to control it.
Good way to compare profiles, but does not measure volume easily.
nj_surfer wrote:
You can compare rail volumes by either making a mold of the rail that's a specific length, and filling it with liquid, and measuring the liquid, or the opposite... make a mold of the rail, fill the mold with pour foam, cut a specific length of that foam, then measure the volume of liquid it displaces when submerged.
Ok, so I didnt read everything before I posted the photo (I'm sorta busy).
Good way to compare profiles, but does not measure volume easily.
nj_surfer wrote:
You can compare rail volumes by either making a mold of the rail that's a specific length, and filling it with liquid, and measuring the liquid, or the opposite... make a mold of the rail, fill the mold with pour foam, cut a specific length of that foam, then measure the volume of liquid it displaces when submerged.
Ok, so I didnt read everything before I posted the photo (I'm sorta busy).
But how is that measuring rail volume EASILY?
If the good people at swaylocks can figure out a way to describe what is rail and what's not (and possibly an industry standard for measuring rail thickness (instead of thick, medium, thin...)), I'll gladly add the volume calculations for the rail to boardcad.
I know of no way to measure rail volume EASILY, and I didn't mean to suggest that I had done any such measurements - just suggesting a way to accurately COMPARE rail volumes.
The next question - where does the rail begin and end - is even more difficult to answer than how to measure it's volume (along different lengths of the board). I would argue that the true rail of a board goes in about 2" from the apex. Further in than that and you're looking more at the bottom or deck than the rail.
I saw two things in this article that I realized almost immediatly; one, The new blanks that are available today both Poly and EPS (due to their consistent densities) allow one to easily adjust rail volume from the deck. The norm with a Clark blank was to take it down to desired thichness from the bottom and to avoid cutting to deep into the deck. Cutting too deep into a Clark deck meant a soft deck. On todays' blanks if the deck is too domed one can safely bring it down to blend it. As Bill suggested changes in rail volume can be made from the deck and with today's consistent blanks there is no sacrifice to deck strength. Two, The other thing is the commonplace "beaked nose" of the 70's and early '80's. Certainly thinning out and rockering the nose as done in modern shortboards has also allowed shapers to alter rail volume in the front third of the blank. Like I said somethings have progressed but, alot of things remain the same. Lowel
I like using this tool. I record my favorite reference and use it to make new ones, with or without volume adjustment. The last one I made I added 1/16" more volume. Imo, deck roll, although related, is another design element.
Good article by BB!
DSC00586.JPG
Good way to compare profiles, but does not measure volume easily. Also, the two rail profiles you show have different shapes and volumes. What was mentioned earlier was changing volume without shape - just scaling up the profile.
Ok got it. I can do all that too.
I took that pic years ago, of two different unrelated boards, both boards work great for me.
My only point was to offer a simple cheap tool that eliminates some of the guesswork.
YMMV.
I've been on the software guys for years to produce a "longitutinal slice". All software has capacity to cut boards across the stringer (and it's easy 9though not emotionally) to slice a board up that way to get rail profiles). The thing hat amazes me about these profiles is how quickly the rail shape changes over say a 1" thick slice of a board. Doesn't seem that it should be much, but when you're handling a block of foam you sure feel it.
A longitudinal slice is needed to get rid of the bunny ears you see in so many machine cut boards, where the software does not merge slices as smoothly as the designer envisioned. Longitudinal slices would also permit accurate foiling of the rails front to rear (what NJ refers to in the middle of his post above). I personally believe that rail foiling should provide lift and drive (like a fin) when the board is on rail.
Watch vids carefully and you can see the nose of many board rising and falling through bottom turns as the rail foiling pops it out the water and the surfer counteracts to keep his line. I've moved my rail thick point forward to change the foiling characteristics. It's tricky moving rail thick point forward of rocker thick point. Keeping rocker thickness the same over the middle 1/3 of the board helps a bit with this.
PS this post shows the other thing that's changed since Bill's excellent article above (thanks for posting!) - machineheads have got into it and are trying to get the ideas to come out of zeros and ones rather than Skils (pun intended)
I think http://www.witchcraft.nu custom software uses longitudional curves for creating the foil, no crossections. However I would think that would be hard to edit. Showing a longitudinal slice on the other hand is relatively easy and something I could incorporate.
Do you attribute this only to rail foil? To me it looks like there are several design elements fighting each other, but it's hard to tell (for me anyway) if it's the rocker that wants to turn at one radius while fins want to trun at another radius or some other element. Sometimes on vids the wobble and bump looks so bad that it's amazing the surfer manages to control it.
Good way to compare profiles, but does not measure volume easily.
Ok, so I didnt read everything before I posted the photo (I'm sorta busy).
But how is that measuring rail volume EASILY?
Are you serious about those measurement methods?
Have you really done that, honestly?
If the good people at swaylocks can figure out a way to describe what is rail and what's not (and possibly an industry standard for measuring rail thickness (instead of thick, medium, thin...)), I'll gladly add the volume calculations for the rail to boardcad.
I know of no way to measure rail volume EASILY, and I didn't mean to suggest that I had done any such measurements - just suggesting a way to accurately COMPARE rail volumes.
The next question - where does the rail begin and end - is even more difficult to answer than how to measure it's volume (along different lengths of the board). I would argue that the true rail of a board goes in about 2" from the apex. Further in than that and you're looking more at the bottom or deck than the rail.
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